You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
50/60HZ, 3x USB Port (Support Quick Charge) Automatically Match Safety-gate Total Design Max Power 2500W 10A 250V Using environment -10℃ ~ +40℃ USB Modle Input 100-240V~, 0.5A USB Output 5V 2.1A Output power 15.5W
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($28.79): BGSTHO15
2. ($28.79): BGHONEY2110
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 2499XM, bgsport, 6OFFXM, affiliate6, 2019SPEDM, bgssaff9, aff7off, BGaDmITAd, BGAQ20, BGSAMH, bGhOnEy10, BGSM15, BGSMOFF, bgshOOp10, BGSAMRTH, BGELIG0920, BgcLuBofErtA10, BG15SH12
(there’s a little possibility that old coupon will work)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi Mijia Four Digit Power Strip? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).